Monitorting And Evaluation Of Vegetation In Area Of Soil Erosion Of Changting County

As an important part of ecosystem,vegetation plays an important role in matter and energy cycle.And it becomes a fundamental measure for soil and water conservation because of its good function of water storage and water conservation.Therefore,monitoring the growth state of the vegetation in the control region is of great significance to the evaluation of the effectiveness of soil erosion control and the evaluation of the regional ecological environment.In this paper,Changting county of Fujian province is chosed as the research area,we use high-quality medium and high spatial resolution time-series data to monitor vegetation growth statue,and study the difference of vegetation restoration under different ways of soil erosion control method.The main research contents and results are summarized as follows:(1)Constrcuting medium spatial resolution time-series data.Firstly,Spatial and Temporal Adaptive Reflectance Fusion Model(STARFM),Adaptive local regression matching algorithm(ALR),together with available Landsat datas were synthetically used to constructe 2000-2015 medium spatial resolution time-series data of Changting County,with a characteristic of year by year and same quarter phase.The analysis results showed that the NDVI curves of different types of ground objects,especially vegetation areas,have good consistency and continuity,which could meet the needs of vegetation status monitoring.(2)Selection of evaluation parameters for vegetation restoration and analysis of change trend of vegetation status.In this paper,we choosed vegetation index,vegetation water content,vegetation nutrition,surface dry degree,surface temperature as monitoring index to objectively show the state of vegetation growth statue.The results showed that the rising trend of the index value in soil erosion control area was faster than that of the vegetation in the non controlled region under vegetation index and vegetation water content index.But the restoration trend of vegetation in the central and southeastern part of Changting County was faster than that of northwest under vegetation nutrition,surface dry degree,surface temperature index.The value of remote sensing index differed between different ways of soil erosion control method.The value of NDVI and GVMI rised the fastest under grass management,and the trend of change was relatively gentle under the way of closure area of vegetation.There was no significant difference in the trend of NRI and LST under different treatments.(3)Construction of comprehensive vegetation state index and evaluation of results.In this paper vegetation status index-VSI was constructed by three different methods.The VSI,constructed by full index principal component analysis and large class principal component analysis,could integrate 80%amount of information of all single index,and the proportion can reach 90%with two principal component analysis method.Based on VSI,constructed by two principal component analysis method,change trend of vegetation state in Changting County and change of VSI in soil erosion control area was analysised.The study results showed that the trend of health restoration of vegetation in the central region of Changting County is the most obvious,and upward trend of VSI in soil erosion control area was faster than that in other non controlled areas.There was a good spatial consistency between the rate of vegetation restoration and different management methods.Specifically,the recovery rate of the control of blocking was most slow,while the rate of garden reform and repeated control was relatively highest.